Fan speed help

spixelspixel · 28 Feb 2018 at 22:37

So I'm trying to make my pc as silent as possible.

There are 2 ways to control the speed of fans connected to the motherboard, through the bios or windows software (asrock extreme tuning utility)

If I use the asrock utility, with the cpu fan speed set to its lowest setting, the speed is 800rpm. However if I go into BIOS and manually set it to its lowest, the speed is 500rpm which is what I want. However if I control my other non pwm fans through the bios, some of them do not start due to the starting voltage not being high enough. However when they are set to low speed in the asrock utility, upon booting the pc the bios setting which is now defaulted to full speed gives them enough starting juice, but for some reason the lowest setting in the asrock utility does not match the lowest setting through bios.

How can I get my cpu fan running slower with the least amount of hassle :confused:

Pocah · 1 Mar 2018 at 08:30

Well you could try different software, say Corsair LINK. BUT ultimately if you want as low as possible and reliable you really need PWM fans all round. Not only that but you need fans that are either tailored to your system ( run in the right RPM range, with the right flow ) or you need to get some wide range hybrid fans like the Corsair ML PRO. The 120mm version of the fan will run from 400RPM all the way up to 2400RPM, so it's really easy to get what you want out of it.

doyll · 1 Mar 2018 at 11:35

Just curious, but what is the problem with fans running at 800rpm? Most even half decent fans are inaudible at about 1.5 meter below 800-900 rpm, and I've found more often than not running fans at lower speed means system temps are higher at idle than under load.

spixelspixel · 1 Mar 2018 at 13:52

doyll said:
Just curious, but what is the problem with fans running at 800rpm? Most even half decent fans are inaudible at about 1.5 meter below 800-900 rpm, and I've found more often than not running fans at lower speed means system temps are higher at idle than under load.

I can hear it at 800rpm but the rest of my pc is extremely quiet. Passive power supply + passive gpu and just 3 very slow case fans. There's a noticeable drop in noise levels if I stop the cpu fan. Its not that its a bad fan either (be quiet c1 advanced is the cooler)

spixelspixel · 1 Mar 2018 at 14:02

Pocah said:
Well you could try different software, say Corsair LINK. BUT ultimately if you want as low as possible and reliable you really need PWM fans all round. Not only that but you need fans that are either tailored to your system ( run in the right RPM range, with the right flow ) or you need to get some wide range hybrid fans like the Corsair ML PRO. The 120mm version of the fan will run from 400RPM all the way up to 2400RPM, so it's really easy to get what you want out of it.

Why do I need pwm fans all round when the rest of my fans are okay and its just the cpu pwm one running faster than required

Pocah said:
Well you could try different software, say Corsair LINK. BUT ultimately if you want as low as possible and reliable you really need PWM fans all round. Not only that but you need fans that are either tailored to your system ( run in the right RPM range, with the right flow ) or you need to get some wide range hybrid fans like the Corsair ML PRO. The 120mm version of the fan will run from 400RPM all the way up to 2400RPM, so it's really easy to get what you want out of it.

My problem is not the range of the fan, its that the software wont set the pwm level as low as the bios. However the rest of my fans are okay through the software and wont start if set low in the bios.

spixelspixel · 1 Mar 2018 at 14:56

Found a workaround for the most part

There were some config files for the asrock utility (6 of the same one for my mobo for some reason) Found the one that worked eventually, you can change the fan settings in there. By default the cpu1&2 which are strangely labeled as 'fan 2' intead of 'fan1' was set to 117 at level by default, I reduced this to 98 and this put the cpu fan speed from 800 to ~620. The only downside is since cpu fan 1&2 are linked this reduced my exhaust fan at the same time to 480rpm. So I also reduced the intake to match

doyll · 1 Mar 2018 at 14:58

spixelspixel said:
I can hear it at 800rpm but the rest of my pc is extremely quiet. Passive power supply + passive gpu and just 3 very slow case fans. There's a noticeable drop in noise levels if I stop the cpu fan. Its not that its a bad fan either (be quiet c1 advanced is the cooler)

Combination of very good ears and very quiet room.

Are you using variable voltage or PWM control in Bios?
I guess the question really is it motherboard or fan PWM that limits the minimum PWM speed? Just curiosity questions.

Never mind, your last post answers my question.

spixelspixel · 1 Mar 2018 at 15:06

doyll said:
Combination of very good ears and very quiet room.

Are you using variable voltage or PWM control in Bios?
I guess the question really is it motherboard or fan PWM that limits the minimum PWM speed? Just curiosity questions.
Never mind, your last post answers my question.

It was the windows software limiting it. Strange how when looking at the config, each fan header has a different value at the same level, its like whoever wrote the file just entered some random numbers.

spixelspixel · 1 Mar 2018 at 15:07

how do i delete a post? :/

Pocah · 2 Mar 2018 at 15:26

spixelspixel said:
Why do I need pwm fans all round when the rest of my fans are okay and its just the cpu pwm one running faster than required

My problem is not the range of the fan, its that the software wont set the pwm level as low as the bios. However the rest of my fans are okay through the software and wont start if set low in the bios.

Because if you are setting the fan speeds really low there is a danger that the fan might stall in future. PWM fans don't stall because if you try to run them too low they wont go below their minimum safe speed. Thing is you just don't know what the safe minimum speed of a non-pwm is. But anyway, like I said, you could try different software to see if that gives you the speed you want. Try Speedfan! That's free. There is a good video on youtube that shows how to set it up correctly.

spixelspixel · 2 Mar 2018 at 23:05

Already found a solution by editing a config file of the asrock software.

Pocah said:
Because if you are setting the fan speeds really low there is a danger that the fan might stall in future. PWM fans don't stall because if you try to run them too low they wont go below their minimum safe speed. Thing is you just don't know what the safe minimum speed of a non-pwm is. But anyway, like I said, you could try different software to see if that gives you the speed you want. Try Speedfan! That's free. There is a good video on youtube that shows how to set it up correctly.